INGREDIENTS
FOR THE CAKE
- 7⅝ ounces Devil’s food cake mix 216 grams, such as Betty Crocker (½ box)
- ⅝ cup water 142 grams
- ¼ cup vegetable oil 50 grams
- 1 large egg 50 grams
- 1 egg yolk 14 grams
FOR THE CHOCOLATE MOUSSE
- 2 teaspoons powdered plain gelatin 6 grams
- 2½ tablespoons cold water 35 grams
- 2¼ cups chocolate chips 383 grams
- 3 cups heavy cream 681 grams, divided
- ½ cup powdered sugar 57 grams
FOR THE GANACHE
- ⅔ cup heavy cream 151 gams
- 8 ounces chocolate chips
- Chocolate shavings optional, for garnish
- Fresh berries optional, for garnish
EQUIPMENT
- Kitchen Scale (optional)
- 9-inch Springform Pan
- Stand Mixer (optional)
- Hand Mixer (optional)
Instructions
FOR THE CAKE
- Prepare ½ package of cake mix according to the instructions on the box. The above ingredient measurements are for ½ box of Betty Crocker Devil’s Food Cake, so be sure to use halved measurements for the appropriate ingredients if you use a different brand of cake mix. If your cake mix calls for 3 eggs, use 1 egg and 1 egg yolk as your halved measurement. Bake in a 9-inch springform pan according to the instructions (around 25 minutes) and let cool on a wire rack while you prepare the mousse.
FOR THE CHOCOLATE MOUSSE
- In a small bowl, combine the gelatin and cold water and bloom for 5-10 minutes.

- Meanwhile, place chocolate chips in a heatproof bowl. In a small saucepan set over medium-high heat, bring 1 cup of heavy cream to a simmer (between 112-115°F), then remove from the heat.
- Whisk in the bloomed gelatin and stir until completely dissolved. Pour mixture over the chocolate chips and whisk until melted and combined. Allow mixture to cool, stirring occasionally.

- In the bowl of a stand mixer fitted with the whisk attachment, or with a hand mixer in a large bowl, beat the remaining 2 cups of cream with the powdered sugar until stiff peaks form.

- Stir about ¼ cup of the whipped cream into the melted chocolate. Gently fold in the remaining whipped cream until fully incorporated.

- Spread the chocolate mousse evenly on top of the cooled cake while still inside the pan.

- Cover with plastic wrap and refrigerate for at least 8 hours or up to overnight.
FOR THE GANACHE
- Once the cake has chilled overnight, place the chocolate chips in a heatproof bowl. In a small saucepan set over medium-high heat, bring 1 cup of heavy cream to a simmer (between 112-115°F), then remove from the heat.
- Pour the warm cream over chocolate chips and allow to sit for 3-4 minutes, then whisk gently until smooth and shiny. Allow to cool until slightly thickened, then pour over the mousse.
- Cover and chill for 1 hour. Serve garnished with chocolate shavings and berries, if desired.
NOTES
- Your mousse needs time overnight to sit before the ganache is poured on top. Do not try to rush this process!
- Devil’s food cake or just regular chocolate cake are both great box mixes to use for this recipe.
- Heavy cream can NOT be substituted with whole milk, or anything else for that matter. Don’t even try it!
- Nutritional information does not include optional ingredients.
Storage: Store chocolate mousse cake in an airtight container in the refrigerator for up to 5 days.

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